The relationship between health insurance characteristics and the use of behavioral health treatment services

Rationale: Many people delay health care treatment and some never seek care from the formal health care system. It is estimated that 28 percent of the U.S. adult population in any year has a diagnosable mental or addictive disorder, and yet less than one-third of these individuals seek treatment. Objective: The objective of this study is to estimate the effect of health insurance characteristics on mental health and substance use (MH/SA) treatment utilization for privately-insured employees and their dependents. Methodology: Using a two-part model, I estimate the effect of MH/SA health insurance characteristics on the decision to use MH/SA services and, conditional on use, the number of treatment days. Probability of use is modeled using a random-effects logit model and the number of treatment days is modeled using a random-effects negative binomial model. Data used are private insurance enrollment and claims data for 1997-1998 from MEDSTAT's Marketscan® database. Results: Individuals are found to respond to expected out-of-pocket expenses for outpatient MH care, but this response is very small. Furthermore, MH/SA health characteristics appear to have little or no effect on SA treatment utilization for spouses and other dependents. My models show that the effect of MH/SA health insurance varies for individuals by their relationship to the policy (i.e., primary beneficiary versus spouse or other dependent). Primary beneficiaries are found to be more responsive to these characteristics iv than spouses and other dependents. When significant, the requirement of precertification by an employee assistance program (EAP) has a negative effect on MH/SA utilization. Conclusions: My findings suggest that the response to cost-sharing for MH care demand is similar to general medical care and brings into question previous arguments against parity for MH/SA treatment. Finally, the role of an EAP is not straightforward. Rather than facilitating treatment access, EAP precertification may create an obstacle to treatment and discourage utilization. However, it is also possible that EAP precertification may decrease formal utilization by providing some brief MH/SA services to individuals with milder conditions